Java8 ：lambda表达式初体验

package lambda;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class FirstTouchLambda {
    public static void main(String[] args) {
        String[] arr= {"Andy","Bill","Cindy","张三","李四","王五",};
        
        for(String name:arr) {
            System.out.println(name);
        }
        
        List<String> nameList = new ArrayList<String>(Arrays.asList(arr));
        
        // filter
        long n=nameList.stream().filter(name->name.startsWith("张")).count();
        System.out.println("张姓人数:"+n);
        
        // loop
        nameList.stream().filter(name->{System.out.println(name+":"+name.length());return name.length()>0;}).count();
        
        // Uppercase
        List<String> ucaseNames=nameList.stream().map(name->name.toUpperCase()).collect(Collectors.toList());
        for(String name:ucaseNames) {
            System.out.println(name);
        }
    }
}

输出：

Andy
Bill
Cindy
张三
李四
王五
张姓人数:1
Andy:4
Bill:4
Cindy:5
张三:2
李四:2
王五:2
ANDY
BILL
CINDY
张三
李四
王五

--2020-03-13--